Minocycline is a member of the broad spectrum tetracycline antibiotics, which has a broader spectrum than the other members of this group of compounds.
Minocycline is widely used in therapy, primarily to treat acne and rosacea at a once daily dose of 100 mg. Minocycline has a unique biological activity profile: it has both antibacterial and anti-inflammatory proprieties.
The preparation of minocycline is, for example, disclosed in U.S. Pat. Nos. 3,148,212; 3,226,436 and 4,849,136.
In general minocycline may be used as the base per se or, for example, as acid addition salt thereof. Until 2008 minocycline base, was known only in the amorphous form.
WO2008102161 describes three crystalline forms of minocycline base which are more stable than the previously known amorphous product.